Dec. 1845.] Action of Magnets on Bismuth and Antimony. 457 



or whether any of them are really so of themselves, I do not 

 undertake to decide at present; nor do I mean to say that the 

 metals of the former list are free. I have been much struck 

 by the apparent freedom from iron of almost all the specimens 

 of zinc, copper, antimony and bismuth, which I have exa- 

 mined ; and it appears to me very likely that some metals, as 

 arsenic, &c, may have much power in quelling and suppressing 

 the magnetic properties of any portion of iron in them, whilst 

 other metals, as silver or platinum, may have little or no 

 power in this respect. 



2294. Resuming the consideration of the influence excited 

 by the magnetic force over those metals which are not mag- 

 netic after the manner of iron (2291.), I may state that there 

 are two sets of effects produced which require to be carefully 

 distinguished. One of these depends upon induced magneto- 

 electric currents, and shall be resumed hereafter (2309.). 

 The other includes effects of the same nature as those pro- 

 duced with heavy glass and many other bodies (2276.). 



2295. All the non-magnetic metals are subject to the mag- 

 netic power, and produce the same general effects as the large 

 class of bodies already described. The force which they then 

 manifest, they possess in different degrees. Antimony and 

 bismuth show it well, and bismuth appears to be especially 

 fitted for the purpose. It excels heavy glass, or borate of 

 lead, and perhaps phosphorus ; and a small bar or cylinder of 

 it about two inches long, and from 0'25 to 0*5 of an inch in 

 width, is as well fitted to show the various peculiar pheno- 

 mena as anything I have yet submitted to examination. 



2296. To speak accurately, the bismuth bar which I em- 

 ployed was two inches long, 0*33 of an inch wide, and - 2 of 

 an inch thick. When this bar was suspended in the mag- 

 netic field, between the two poles, and subject to the magnetic 

 force, it pointed freely in the equatorial direction', as the heavy 

 glass did (2253.), and if disturbed from that position returned 



freely to it. This latter point, though perfectly in accordance 

 with the former phenomena, is in such striking contrast with 

 the phaenomena presented by copper and some other of the 

 metals (2309.), as to require particular notice here. 



2297. The comparative sensibility of bismuth causes several 

 movements to take place under various circumstances, which 

 being complicated in their nature, require careful analysis and 

 explanation. The chief of these, with their causes, I will pro- 

 ceed to point out. 



2298. If the cylinder electro-magnet (2246.) be placed ver- 

 tically so as to present one pole upwards, that pole will exist 

 in the upper end of an iron cylinder, having a flat horizontal 



Phil. Mag. S. 3. Vol. 28. No. 189. June 1846. 2 I 



